Panel and method for the preparation thereof

Abstract

Composite foam panels are prepared from expanded thermoplastic particles of low density by generally encapsulating the particles in a phenolic foam matrix and providing a particulate expanded mineral substance such as perlite disposed generally adjacent the major surfaces of the panel.

What is claimed is: 
     
       1. A method for the manufacture of a composite synthetic resinous foam panel having at least first and second major generally parallel surfaces, the steps of the method comprising providing a mold, the mold when in the closed position having at least two major internal surfaces corresponding to the major surfaces of the panel disposed within the mold, disposing on the surfaces of the mold a foamable resole resin composition containing admixed therewith a particulate expanded inorganic glass, disposing within the open mold an expanded particulate synthetic resin mass in the form of a plurality of particles, the quantity of expanded synthetic resinous thermoplastic particles being about equal to or up to about twenty percent in excess of the volume of the mold, closing the mold to thereby sandwich the synthetic resinous thermoplastic particles between said two layers of foam forming resole resin composition and partially compressing the synthetic resinous thermoplastic particles, said particles having interstitial spaces therebetween, heating the foaming resole resin composition to a foam forming temperature, the resole resin composition being present in a quantity sufficient that on foaming the resole resinous composition permeates the interstitial spaces between the synthetic resinous particles, the resole resin curing and hardening to form an integral panel having a density of from about 1.5 to 5 pounds per cubic foot. 
     
     
       2. The method of claim 1 wherein the expanded synthetic resinous thermoplastic particles are styrene polymer. 
     
     
       3. The method of claim 1 wherein the expanded glass is perlite. 
     
     
       4. The method of claim 1 wherein the synthetic resinous thermoplastic particles have the size of from about 1/16 of an inch to 3/8 of an inch. 
     
     
       5. The method of claim 1 wherein the expanded synthetic resinous thermoplastic particles are styrene polymer, the expanded glass is perlite and the styrene polymer particles have an average diameter of from about 1/16 of an inch to 3/8 of an inch. 
     
     
       6. The method of claim 1 including the step of adhering an aluminum sheet to at least one major surface of the panel.